1. Field of the Invention
The present invention relates to steroid derivatives having aldosterone-antagonistic activity more potent than that of spironolactone.
2. Description of the Prior Art
The aldosterone antagonists have widely been used alone in diagnosis and improvement of condition of primary aldosteronism, or together with other drugs in treatment of essential or renal hypertension as well as cardiac or renal edema since they antagionize aldosterone in the distalis urinary tubule to inhibit resorption of sodium and excretion of potassium and exhibit diuretic effect without causing potassium loss.
Spironolactone [The Merck Index 10th Edition 8610] is a well known aldosterone antagonist. As the analogous compounds of spironolactone are exemplified potassium canrenoate [Clin. Pharm. Ther. 21, 602 (1977)], potassium mexrenoate [J. Pharmacol. Exp. Ther. 209, 144 (1979)], potassium prorenoate [Clin. Pharm. Ther. 18, 391 (1975)], spirorenone [Japanese Unexamined Patent Publication No. 55-162799], and the like. In addition to the above aldosterone antagonists, various steroidal derivatives have been found out as antagonists, among which the compound having a double bond at the C.sub.11 -C.sub.12 position shown by the following formula is described in French Medicinal Pat. No. 7871. ##STR1##